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Clays, Clay Minerals and Ceramic Materials Based on Clay Minerals Edited by Gustavo Morari do Nascimento Clays, Clay Minerals and Ceramic Materials Based on Clay Minerals Edited by Gustavo Morari do Nascimento Stole src from http://avxhome.se/blogs/exLib/ Published by ExLi4EvA Copyright © 2016 All chapters are Open Access distributed under the Creative Commons Attribution 3.0 license, which allows users to download, copy and build upon published articles even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. After this work has been published, authors have the right to republish it, in whole or part, in any publication of which they are the author, and to make other personal use of the work. Any republication, referencing or personal use of the work must explicitly identify the original source. As for readers, this license allows users to download, copy and build upon published chapters even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. Notice Statements and opinions expressed in the chapters are these of the individual contributors and not necessarily those of the editors or publisher. No responsibility is accepted for the accuracy of information contained in the published chapters. The publisher assumes no responsibility for any damage or injury to persons or property arising out of the use of any materials, instructions, methods or ideas contained in the book. Publishing Process Manager Technical Editor AvE4EvA MuViMix Records Cover Designer Спизжено у ExLib: avxhome.se/blogs/exLib First published March 11, 2016 Stole src from http://avxhome.se/blogs/exLib: ISBN-10:С 9п5и3-з5ж1-е2н25о9 -у2 ExLib: avxhome.se/blogs/exLib ISBN-13: 978-953-51-2259-3 C ontents Preface Chapter 1 Structure of Clays and Polymer–Clay Composites Studied by X-ray Absorption Spectroscopies by Gustavo M. Do Nascimento Chapter 2 Clay Minerals and Clay Mineral Water Dispersions — Properties and Applications by Guadalupe Sanchez-Olivares, Fausto Calderas, Luis Medina- Torres, Antonio Sanchez-Solis, Alejandro Rivera-Gonzaga and Octavio Manero Chapter 3 Charging Behavior of Clays and Clay Minerals in Aqueous Electrolyte Solutions — Experimental Methods for Measuring the Charge and Interpreting the Results by Tajana Preocanin, Ahmed Abdelmonem, Gilles Montavon and Johannes Luetzenkirchen Chapter 4 Adsorption of Industrial Pollutants by Natural and Modified Aluminosilicates by Liudmila Novikova and Larisa Belchinskaya Chapter 5 Structural and Electrochemical Properties of Cementitious and Hybrid Materials Based on Nacrite by Nouha Jaafar, Hafsia Ben Rhaiem and Abdesslem Ben Haj Amara Chapter 6 Clay/Biopolymer Composite and Electrorheological Properties by Mehmet Cabuk Chapter 7 Ceramic Materials Based on Clay Minerals in Cultural Heritage Study by Rodica-Mariana Ion, Radu-Claudiu Fierăscu, Sofia Teodorescu, Irina Fierăscu, Ioana-Raluca Bunghez, Daniela Ţurcanu- Caruţiu and Mihaela-Lucia Ion Preface This book presents the state-of-the-art results of characterization of clays, clay minerals and ceramic materials based on clay minerals. The main goal of this work is to contribute to the rationalization of some important results obtained in the open area of clays and clay materials characterization. Moreover, this book also provides a comprehensive account on polymer and biopolymer-clay nanocomposites, use of clay as adsorption materials for industrial pollutants, ceramic materials in cultural heritage and physical-chemistry aspects of clay and clay minerals aqueous dispersions. This book will be beneficial for students, teachers and researchers of many areas who are interested to expand their knowledge about clays and its derivates in the fields of Nanotechnology, Biotechnology, Environmental Science, Industrial Remediation, Cultural Heritage, etc. Chapter 1 Structure of Clays and Polymer–Clay Composites Studied by X-ray Absorption Spectroscopies Gustavo M. Do Nascimento Additional information is available at the end of the chapter http://dx.doi.org/10.5772/61788 Abstract A wide range of spectroscopic techniques employ higher-energy electromagnetic radiation, ranging from vacuum UV (≈10−40 eV, 125−31 nm), including soft X-rays (40−1500 eV, 31−0.8 nm), and going to hard X-rays (1500−105 eV, 0.8−0.01 nm) for elucidating molecular structures of chemical and biological interest. A typical X-ray absorption (XAS) spectrum has a large absorption near the edge followed by serial oscillations that gradually fade away. This set of oscillations extends over a wide energy range and can be divided into two regions: the absorption near the edge is called XANES (X-ray absorption near-edge structure) and the second region is the so-called EXAFS (extended X-ray absorption fine structure). The XAS data enables the determination of crystallographic parameters and also the signal intensity con‐ tains information of the oxidation state and the chemical bond in the solid. For in‐ stance, theoretical calculations were essential to verify the differences between the oxygen and silicon sites in clays. Experimental and theoretical EXAFS studies of clays with Cu(II) show that Cu(II) has interchangeable octahedral, tetragonal, and square planar coordinations in the clay interlayer, depending on Cu(II) loading and degree of hydration. XANES data of intercalated poly(aniline) show new bands at 398.8 eV and 405−406 eV, which were assigned to new chromophoric segments formed within the galleries of the Montmorillonite clay. Hence, in this chapter, this amazing new area will be reviewed concerning the state-of-the-art results of charac‐ terization of their structural features. Previous and new results of the X-ray absorp‐ tion spectroscopy of clays and polymer–clay materials obtained by our group will be considered. The main goal of this work is to contribute to the rationalization of some important results obtained in the open area of clays and clay materials charac‐ terization. Keywords: XANES, Clays, Ceramics, EXAFS 2 Clays, Clay Minerals and Ceramic Materials Based on Clay Minerals 1. Introduction 1.1. Clays, clay minerals, and ceramics The term clay can assume different meanings for different groups of people. For the farmer, clays are the mechanical and chemical environment where most plants grow. For the ceramist, it is the raw material of his works for over 4000 years. To the editor, it gives softness to the paper’s surface in high-quality prints. In the medical area, it may be for the relief of diarrhea and so on. In fact, there is no uniform nomenclature for clay and clay materials [1, 2]. Georgius Agricola (1494–1555), the founder of geology, was apparently the first to propose a definition for clay [3]. The last definition is that the term clay can be considered as natural fine-grained minerals with plastic behavior at appropriate water contents that will harden when dried or fired. Generally, in the area of geology, clays are considered as particles with a size dimension of <4 μm, while in colloid science, a value of <1 μm is more acceptable [4, 5]. Likewise, the term “clay mineral” is difficult to define. As a first approximation, the term signifies a class of hydrate phyllosilicates making up the fine-grained fraction of rocks, sediments, and soils. The definition that the JNCs have proposed is “...phyllosilicate minerals and minerals which impart plasticity to clay and which harden upon drying or firing” [3] Since the origin of the mineral is not part of the definition, clay mineral (unlike clay) may be synthetic. Hence, clay minerals are extremely fine materials that can only be studied in detail by using X-ray techniques or sophisticated microscopic techniques, such as the electron scanning microscope [6]. They are primarily hydrated aluminosilicates in which the magnesium and iron can replace the aluminum wholly or partly with alkaline or alkaline earth elements. Thus, its chemical composition is variable, such as the nature of the interlayer cations and water content. The different clay minerals have different dehydration properties, structural failure limits, decomposition products, cation exchange capacity (CEC), and other useful properties of economic interest. Clays layers are formed from tetrahedral sheets in which a silicon atom is surrounded by four oxygen atoms and octahedral sheets in which a metal such as aluminum or magnesium is surrounded by eight oxygen atoms [1-3, 7]. The tetrahedral (T) and octahedral (O) sheets are bonded by the oxygen atoms. Unshared oxygen atoms are present in hydroxyl form. Two main arrangements of T and O layers are observed in major parts of clays. One tetrahedral fused to one octahedral (1:1) is known as the kaolin group, with a general composition of AlSiO(OH) and a layer thickness of ~0.7 nm. Phyllosilicates are formed by one octahedral 2 2 5 5 sheet bonded between two tetrahedral sheets (2:1) with a total thickness of 0.94 nm. When the aluminum cations in the octahedral layers are partially substituted by divalent magnesium or iron cations, the smectite clay group is formed, whose structure consists of a central sheet containing groups MO(OH) of octahedral symmetry associated with two tetrahedral sheets 4 2 (MO) producing layers designated as T:O:T (see Figure 1.) [7]. The octahedral sites are 4 occupied by ions of aluminum, iron and magnesium, while the centers accommodate tetra‐ hedrons of silicon and aluminum ions. The negative charges from the T:O:T lamellae are neutralized by hydrated alkaline cations that can be exchanged with any other cationic species. Mainly, smectite clays exhibit surface adsorption and catalytic activity in organic reactions.